Patent GB-202959-A (GB)
Title: Improved stopping mechanism for talking machines
IPC: G11B17/02
Filed: 1923-05-22
Abstract: 202,959. Victor Talking Machine Co., (Assignees of Calderwood, F. S., and Zeruneith, R. E.). Aug. 26, 1922, [Convention date]. Brakes; starting and stopping. - A pivoted stopping-member adapted to be pulled by a spring into position for applying a brake or opening a switch has an abutment member pivoted thereon, with which abutment a detent is adapted to engage end to end. During such engagement the stopping-member is held in inoperative position, but it is released when the abutment and the detent are disengaged either by hand or automatically by the action of the tone-arm at the end of a record, or after the machine has run for a determined period. The construction shown is applied to a machine driven by an electromotor, in the circuit of which is a switch controlled by a member 26 pivoted at 27. Mounted on a pivot 29 on the part 26 is a member 28 which has a projection 46 acting as an abutment for a detent arm 32. This arm, which is connected by a spring 45 to the member 26, is pivoted at 31, and is frictionally connected to a fork 35, one branch 37 having a setting-handle 39 and the other 36 being arranged to be engaged by a projection 38 from the tone-arm. The engaging faces of the abutment 46 and of the end of the arm 32 fit squarely together and are substantially at right-angles to the line joining the pivots 29 and 31, so that there is little friction between the faces. A handle 30 projects from the member 28. The stopping- member 26 is slotted at 25 to engage an arm 23 extending upwardly therethrough from one of the switch-members (not shown). When the parts are in the position shown, the switch is closed for operation of the gramophone. The arm 35 having been previously adjusted to the proper position, at the end of the playing of a record the pin 38 pushes against the arm 36, thereby shifting the detent 32 aside from the abutment 46. The spring 45 thereupon rotates the member 26, which, acting on the arm 23, throws open the switch. To stop the machine by hand, the member 28 may be turned out of engagement with the detent 32 by means of the handle 30, thus allowing the spring 45 to act as described above. In order to switch off the motor automatically after it has been running for a given time, when for any reason the tone-arm has been prevented from effecting the stoppage, mechanism is provided whereby the abutment member 28 is under the control of a wheel slowly driven by the motor. As shown, a link 74 pivoted to the part 28 carries a pawl 75 which engages with a ratchet-wheel 71 driven by reducing-gear from the turntable spindle 3. The pawl is moved by the ratchet so as to abut against the end of the link 74 and thus the thrust transmitted through the link slowly turns the member 28 about its pivot. The link is shifted outwardly when a cam 81 thereon engages a stud 82. This movement allows the pawl 75 to clear the ratchet-wheel, and, when the mechanism is reset by means of the handle 30, to be brought into position to be engaged by a fresh tooth of the ratchet. A modification of somewhat different design is described in which, instead of controlling an electric switch, the stopping- member 26 carries a brake-pad adapted to be applied to the rim of the turntable.